S. 263 : Commissioner-Revision of orders prejudicial to revenue-Lack of enquiry-Leasehold rights in land and building duly examined by Assessing Officer-Valuation based on registered valuer’s report-Reversal of provision disallowed u/s 43B cannot be taxed on write-back-Revision not sustainable-Tribunal quashing revision affirmed. [S. 43B, 56(2)(x), 260A].